PRIMARY RAT LACRIMAL CELLS UNDERGO ACINAR-LIKE MORPHOGENESIS ON RECONSTITUTED BASEMENT-MEMBRANE AND EXPRESS SECRETORY COMPONENT UNDER ANDROGEN STIMULATION

Single cells or small cell clusters, isolated from the rat lacrimal gl and, were incubated on reconstituted basement membrane (matrigel) in a well-defined serum-free medium. During the first days of culture, cel ls reassociated and reorganized in structures resembling acini. These multicellular structures, maintained in culture for 2 weeks, consisted of well-polarized cuboidal cells surrounding a central lumen and exhi biting apically located microvilli. Myoepithelial cells were observed at the periphery of the acinar structures. Both in the native lacrimal and in the cultured aggregates, epithelial cells displayed strong imm unoreactivity for cytokeratin 8, while myoepithelial cells were immuno reactive for vimentin and alpha-smooth muscle isoactin. These data ind icate that the cultured aggregates closely mimic the in vivo architect ure of lacrimal glands both by morphology and immunohistochemistry. We further demonstrated the presence of an intact androgen receptor and the ability of the cultured aggregates to respond to androgens with in creased secretion of the secretory component. Comparable androgen resp onses were observed in lacrimal gland cultures of 5-week-old male and female rats. In conclusion, we report a morphologically and functional ly differentiated culture system of primary rat lacrimal cells, in whi ch androgen-regulated gene expression was observed. This culture model provides a unique experimental paradigm for studying the effects of h ormones, cytokines, and growth factors on the morphogenesis, growth, a nd functional differentiation of lacrimal glands. (C) 1998 Academic Pr ess.